As one of visible light communication techniques for transmitting information by using visible light, there is known a communication system in which a transmitting apparatus irradiates an object with light on which information is superimposed and a reception apparatus images the object to detect the superimposed information. According to this communication system, it is possible to distribute information related to an object irradiated with light to a smart device or the like equipped with a camera.
A digital watermark technique for embedding additional information in an image, a technique for multiplexing additional information in compressed image data, and the like are also known.
In the case of embedding information in illumination light to irradiate an object and providing a video obtained by imaging a scene including the object to a user, the signal representing the information embedded in the video becomes weak and it may be difficult to detect the information from the video.
The followings are reference documents.    [Document 1] International Publication Pamphlet No. WO 2016/001972,    [Document 2] Japanese Laid-open Patent Publication No. 2002-344720,    [Document 3] Japanese Laid-open Patent Publication No. 2005-39603, and    [Document 4] Japanese Laid-open Patent Publication No. 2004-312663.